| Message ID | 1446761724-5191-1-git-send-email-aaro.koskinen@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/06/2015 12:15 AM, Aaro Koskinen wrote: > We cannot put the HW RNG to idle using a timer because we cannot disable > clocks from atomic context. Use a delayed work instead. > > Fixes a warning with CONFIG_DEBUG_MUTEXES on Nokia N900 during boot. > > Reported-by: Sebastian Reichel <sre@kernel.org> > Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> > --- > drivers/char/hw_random/omap3-rom-rng.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c > index a405cdc..58191c6 100644 > --- a/drivers/char/hw_random/omap3-rom-rng.c > +++ b/drivers/char/hw_random/omap3-rom-rng.c > @@ -29,11 +29,11 @@ > /* param1: ptr, param2: count, param3: flag */ > static u32 (*omap3_rom_rng_call)(u32, u32, u32); > > -static struct timer_list idle_timer; > +static struct delayed_work idle_work; > static int rng_idle; > static struct clk *rng_clk; > > -static void omap3_rom_rng_idle(unsigned long data) > +static void omap3_rom_rng_idle(struct work_struct *work) > { > int r; > > @@ -51,7 +51,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count) > u32 r; > u32 ptr; > > - del_timer_sync(&idle_timer); > + cancel_delayed_work_sync(&idle_work); > if (rng_idle) { > clk_prepare_enable(rng_clk); > r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT); > @@ -65,7 +65,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count) > > ptr = virt_to_phys(buf); > r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW); > - mod_timer(&idle_timer, jiffies + msecs_to_jiffies(500)); > + schedule_delayed_work(&idle_work, msecs_to_jiffies(500)); > if (r != 0) > return -EINVAL; > return 0; > @@ -102,7 +102,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) > return -EINVAL; > } > > - setup_timer(&idle_timer, omap3_rom_rng_idle, 0); > + INIT_DELAYED_WORK(&idle_work, omap3_rom_rng_idle); > rng_clk = devm_clk_get(&pdev->dev, "ick"); > if (IS_ERR(rng_clk)) { > pr_err("unable to get RNG clock\n"); > @@ -118,6 +118,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) > > static int omap3_rom_rng_remove(struct platform_device *pdev) > { > + cancel_delayed_work_sync(&idle_work); > hwrng_unregister(&omap3_rom_rng_ops); > clk_disable_unprepare(rng_clk); > return 0; > Sry, It looks like PM runtime autosuspend might work well here. What do you think?
On Fri, Nov 06, 2015 at 12:15:24AM +0200, Aaro Koskinen wrote: > We cannot put the HW RNG to idle using a timer because we cannot disable > clocks from atomic context. Use a delayed work instead. > > Fixes a warning with CONFIG_DEBUG_MUTEXES on Nokia N900 during boot. > > Reported-by: Sebastian Reichel <sre@kernel.org> > Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Thanks for the patch. Can you please remove timer.h and include workqueue.h instead? Cheers,
diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c index a405cdc..58191c6 100644 --- a/drivers/char/hw_random/omap3-rom-rng.c +++ b/drivers/char/hw_random/omap3-rom-rng.c @@ -29,11 +29,11 @@ /* param1: ptr, param2: count, param3: flag */ static u32 (*omap3_rom_rng_call)(u32, u32, u32); -static struct timer_list idle_timer; +static struct delayed_work idle_work; static int rng_idle; static struct clk *rng_clk; -static void omap3_rom_rng_idle(unsigned long data) +static void omap3_rom_rng_idle(struct work_struct *work) { int r; @@ -51,7 +51,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count) u32 r; u32 ptr; - del_timer_sync(&idle_timer); + cancel_delayed_work_sync(&idle_work); if (rng_idle) { clk_prepare_enable(rng_clk); r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT); @@ -65,7 +65,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count) ptr = virt_to_phys(buf); r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW); - mod_timer(&idle_timer, jiffies + msecs_to_jiffies(500)); + schedule_delayed_work(&idle_work, msecs_to_jiffies(500)); if (r != 0) return -EINVAL; return 0; @@ -102,7 +102,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) return -EINVAL; } - setup_timer(&idle_timer, omap3_rom_rng_idle, 0); + INIT_DELAYED_WORK(&idle_work, omap3_rom_rng_idle); rng_clk = devm_clk_get(&pdev->dev, "ick"); if (IS_ERR(rng_clk)) { pr_err("unable to get RNG clock\n"); @@ -118,6 +118,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) static int omap3_rom_rng_remove(struct platform_device *pdev) { + cancel_delayed_work_sync(&idle_work); hwrng_unregister(&omap3_rom_rng_ops); clk_disable_unprepare(rng_clk); return 0;
We cannot put the HW RNG to idle using a timer because we cannot disable clocks from atomic context. Use a delayed work instead. Fixes a warning with CONFIG_DEBUG_MUTEXES on Nokia N900 during boot. Reported-by: Sebastian Reichel <sre@kernel.org> Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> --- drivers/char/hw_random/omap3-rom-rng.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)